1. Field of the Invention
The present invention is directed to a method for operating an engine, such as a dual-fuel engine, in a manner that provides improved combustion of the air/gas mixture and increased efficiency of engine operation, and to a control device for implementing the inventive method.
2. Background of the Invention
In known so-called dual-fuel engines, a liquid fuel such as diesel can be burned in a liquid fuel operating mode and a gaseous fuel such as natural gas can be burned in a gaseous fuel operating mode of the engine. Generally, in the gaseous fuel operating mode a lean air/gas mixture is injected into the cylinders of the engine and ignited by the ignition energy of an ignition fluid which is likewise injected into the cylinders. To provide this functionality, a dual-fuel engine includes an ignition fluid injection system that has an ignition fluid delivery pump shared by a plurality of cylinders, an ignition fluid reservoir shared by a plurality of cylinders, and individual ignition fluid injectors for the plurality of cylinders. In operation, the ignition fluid is injected into each respective cylinder shortly before top dead center of the cylinder piston in the combustion chamber of the cylinder, i.e. with a single injection per power stroke of the cylinder.